RE: flattened primers
A flattened primer aloneis not, in itself, an indication of high pressure. A flattened primer along with a hard to lift bolt, loosened primer, a shiny case head where thebrass flowed into the ejector hole,or brass that has flowed into the extractor groove are definite indicators of high pressure. In two of my .30-06s, i get away with using a load of 3031thatistwo tofour grains above anyones printed maximum load for a 150 grain bullet: But this can only be accomplished with the use of Winchester cases.